Galvanizing fluxes

Abstract

A chloride based galvanizing flux containing at least zinc chloride, ammonium chloride and a rare earth chloride. The rare earth chloride comprises between substantially 500 parts per million and substantially 10% by weight of said flux.

What is claimed is: 
     
       1. A chloride based galvanising flux containing at least zinc chloride, ammonium chloride and a rare earth chloride, said rare earth chloride comprising between substantially 500 parts per million and substantially 10% by weight of said flux. 
     
     
       2. A chloride based galvanising flux as claimed in claim 1 wherein said rare earth chloride comprises between substantially 1,500 parts per million and substantially 3% by weight of said flux. 
     
     
       3. A chloride based galvanising flux as claimed in claim 1 wherein said rare earth chloride comprises a mixture of rare earth chlorides in proportions substantially similar to the proportions of rare earth elements in mischmetal. 
     
     
       4. A chloride based galvanising flux as claimed in claim 1 wherein said rare earth chlorides comprise cerium chloride or lanthanum chloride or a mixture thereof. 
     
     
       5. A chloride based galvanising flux as claimed in claim 1 wherein said flux comprises an aqueous solution containing at least 200 parts per million by weight of total solution of said rare earth chloride. 
     
     
       6. A chloride based galvanising flux as claimed in claim 5 wherein said aqueous solution includes less than 2% by weight of total solution of said rare earth chloride. 
     
     
       7. A method of preparing a galvanising flux comprising adding an activator containing a rare earth chloride to a chloride based galvanising flux containing at least zinc chloride and ammonium chloride so that said flux contains between substantially 500 parts per million and substantially 10% by weight of rare earth chloride. 
     
     
       8. A method of preparing a galvaanising flux as claimed in claim 9 wherein said flux contains between substantially 1,500 and substantially 3% by weight of rare earth chloride. 
     
     
       9. A method of preparing a galvanising flux as claimed in claim 7 wherein said flux is an aqueous flux containing zinc and ammonium chloride said method comprising the steps of adding an activator containing a rare earth chloride to said flux so that the said aqueous flux contains at least 200 ppm by weight of total solution of said rare earth chloride and less than 2% by weight of said rare earth chloride.